Abstract: A cam adjustment device for lifting and lowering an armrest includes an armrest assembly and a support frame. The armrest assembly includes a connection base. The support frame has a support rod. The connection base is slidably connected to the support rod. A locking mechanism includes a cam wrench disposed on the connection base and rotatably installed on the connection base. The cam wrench is rotated such that a cam on the cam wrench presses and acts on the support rod. In a locked state, the cam wrench presses the support rod such that the connection base and the support rod are kept to be relatively fixed. In an unlocked state, the cam wrench is rotated to allow the cam to be released from the support rod, such that the connection base is lifted, lowered, and adjusted relative to the support rod.

Abstract: A cam adjustment device for lifting and lowering an armrest includes an armrest assembly and a support frame. The armrest assembly includes a connection base. The support frame has a support rod. The connection base is slidably connected to the support rod. A locking mechanism includes a cam wrench disposed on the connection base and rotatably installed on the connection base. The cam wrench is rotated such that a cam on the cam wrench presses and acts on the support rod. In a locked state, the cam wrench presses the support rod such that the connection base and the support rod are kept to be relatively fixed. In an unlocked state, the cam wrench is rotated to allow the cam to be released from the support rod, such that the connection base is lifted, lowered, and adjusted relative to the support rod.

Abstract: An ergonomic chair includes a back component and a seat component. The back component includes an upper back support, a lower back support, a seat back frame that is elastically deformed under traction or squeezing, and a locking mechanism for maintaining positions of the above three components to be relatively fixed. The lower back support is connected to the seat component through a connecting rod. A lower end of the upper back support is rotatably connected to an upper end of the lower back support. Upper and lower ends of the seat back frame are respectively hinged on an upper portion of the back support and the lower portion of the lower back support.

Abstract: An ergonomic chair includes a back component and a seat component. The back component includes an upper back support, a lower back support, a seat back frame that is elastically deformed under traction or squeezing, and a locking mechanism for maintaining positions of the above three components to be relatively fixed. The lower back support is connected to the seat component through a connecting rod. A lower end of the upper back support is rotatably connected to an upper end of the lower back support. Upper and lower ends of the seat back frame are respectively hinged on an upper portion of the back support and the lower portion of the lower back support.